Electrical switches with precise locating means between the carriage and contactor



"March 10, 1970 M. F. BED OCS 3,500,002

ELECTRICAL SWITCHES WITH PRECISE LOCATING MEANS BETWEEN I THE CARRIAGE AND CONTACTOR Filed m. 29, 1968 2 Sheets-Sheet 1 J J G a;gj

M. F. BEDOCS 3,500,002

March 10, 1970' Y ELECTRICAL SWITCHES WITH PRECISE LOCATING MEANS BETWEEN THE CARRIAGE AND CONTACTOR 2 Sheets-Sheet 2 Filed Jan. 29, 1968 3 T20 I q 232 510p [/6117 Z225 n United States Patent ELECTRICAL SWITCHES WITH PRECISE LOCATING MEANS BETWEEN THE CARRIAGE AND CONTA'CTOR Michael F. Bedocs, Wilmette, Ill., assignor to Indak Manufacturing Corp., Northbrook, 11]., a corporation of Illinois Filed Jan. 29, 1968, Ser. No. 701,321 Int. Cl. H01h 15/24 US. Cl. 200-16 9 Claims ABSTRACT OF THE DISCLOSURE An electrical switch having a casing, an insulating carriage movable in said casing, an insulating wall on said casing, a plurality of contacts mounted on said wall, a contactor movable withsaid carriage and engageable with said contacts, and spring means biasing said contactor toward said contacts, said contactor being plate-like and having opposite edge portions formed 'with a pair of locating notches, said carriage having a pair of opposed lugs closely received in said notches and locating said carriage for precise movement therewith.

This invention relates to electrical switches. While the invention is applicable to switches generally, it is particularly applicable to switches intended primarily for antomotive service, on automobiles, trucks and other vehicles.

Prior automotive switches have generally included a casing, an insulating carriage movable in the casing, an insulating wall on the casing, a plurality of contacts mounted on the insulating wall, a contactor movable with the carriage and engageable with the contacts, and spring means on the carriage and biasing the contactor toward the contacts. In prior switches, the contactor has generally been formed With prongs, slidably received in slots formed in the contactor. The prongs would cause the contactor to move with the carriage, while providing for sliding movement of the contactor toward the contacts.

A trend has become apparent in some types of automotive switches to require a high order of precision in the operation of the switch. It has been found that such preci sion is difficult or impossible to achieve with the usual construction involving prongs on the contactor, slidable in slots formed in the carriage. This construction generally results in considerable lost motion or play between the contactor on the carriage. At least one, and preferably a operating precision of the switch.

In accordance with the present invention, a high order of precision is achieved by dispensing with the usual prongs, and providing improved means for locating the contactor on the carriage. At least one, and preferably a plurality of notches or slots are formed in edge portions of the contactor. The carriage is formed with lugs or guide bars which are closely received in the notches. The engagement between the notches and the lugs provides for outward sliding movement of the contactor toward the contacts. At the same time, the lugs may be closely fitted into the notches, so as to minimize lost motion or play between the contactor and the carriage. In this way, the contactor follows the movement of the carriage with a high order of precision, so that there is very little variation in the operating cycle of the switch. Such precise switch operation is an important advantage in motion sensing switches, such as brake switches, for example.

In accordance with another feature of the present invention, the switch is preferably provided with a single contact rivet at one point along the path of movement of the contactor, and a pair of contact rivets on opposite sides of such path, spaced therealong from the single contact rivet. First and second terminals are connected to the single contact rivet and the pair of rivets. The terminals are preferably of identical construction, with a central opening adapted to receive the single contact rivet, and a pair of openings adapted to receive the pair of contact rivets. Thus, the terminals are interchangeable, so as to facilitate the assembly of the switch. The switch may also have another contact rivet, which is also adapted to receive a terminal of identically the same construction.

The additional contact rivet is adapted to be received in an additional opening in the insulating contact board. When the additional rivet is not used, such opening is occupied by a semi-perforated member which does not interfere with the operation of the switch, and may be knocked out of the opening when the additional contact rivet is to be inserted.

Further objects, advantages and features of the present invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is a plan view of a switch to be described as an illustrative embodiment of the present invention.

FIG. 2 is a side elevation of the switch.

FIG. 3 is a front elevation of the switch.

FIG. 4 is an enlarged plan view of the switch, with the terminal board removed and shown alongside the switch.

FIG. 5 is a section, taken along the line 55 in FIG. 6.

FIG. 6 is a longitudinal section, taken generally along the line 6-6 in FIG. 5.

FIG. 7 is a perspective view of the contactor for the switch.

FIG. 8 is a perspective view of the carriage for the switch.

FIG. 9 is a perspective view of one of the terminals for the switch.

FIG. 10 is a diagrammatic section showing a modified construction.

FIG. 11 is a plan view showing the contact board for the modified construction of FIG. 10.

As already indicated, FIGS. 1-9 illustrate an electrical switch 20 with will find many uses, but is particularly applicable to automotive service, in connection with automobiles, trucks and other vehicles. The illustrated switch 20 is intended particularly to control the brake or stop lights on an automobile or other vehicle. The switch is adapted to be operated by the brake pedal of the automobile. When the brake pedal is in its normal or unactuated position, a portion of the pedal actuates the switch so as to open the circuit for the stop lights. When the brake pedal is actuated, the switch is allowed to retum to its normal or unactuated position, in which the circuit for the stop lights is closed.

The illustrated switch 20 comprises a casing or housing 22 which is preferably made of metal, but may be made of any other suitable material. A mounting bracket 24 is shown as being secured to the casing 22. As illustrated, the casing 22 is generally rectangular in shape, and is formed with a bottom wall 26, a pair of longitudinal side walls 27 and 28, and a pair of end walls 29 and 30.

A carriage 32 is movably mounted within the casing 22. The carriage 32 is preferably made of an insulating material, such as a suitable resinous plastic material, but various other suitable materials may be employed. Means are provided to operate the carriage 32 within the casing 22. In this case, the carriage 32 is formed with a pin or plunger 34 which projects out of the casing 22 through an opening 36 in the end wall 30. When the switch 20 is is used as a brake switch, the plunger 34 is adapted to be operated by a portion of the brake pedal.

The illustrated carriage 32 is generally rectangular in shape and is movable along a linear path within the casing 22. Runners or ridges 38 are formed on the carriage 32 for sliding engagement with the bottom wall 26 of the casing 22. The illustrated carriage 32 has a pair of longitudinal side wall portions 39 and 40 which are slidably engageable with the longitudinal side walls 27 and 28 of the casing 22. It will be seen that the carriage 32 is slidable longitudinally within the casing 22, between the opposite end walls 29 and 30.

The illustrated switch is of the push button type, having resilient means in the form of a spring 42 for biasing the carriage 32 toward its initial or unactuated position. In this case, the spring 42 is of the coil compression type, acting between the carriage 32 and the end wall 29. Thus, the spring 42 biases the carriage 32 against the end wall 30, in the initial position of the switch. In the illustrated construction, the locating slot or channel 44 is formed in the lower portion of the carriage 32, to receive one end portion of the spring 42. The other end portion of the spring 42 is preferably located by a boss or projection 46, formed inwardly from the end wall 29 of the casing 22.

The carriage 32 is provided with a contactor 48 which is movable with the carriage. The contactor 48 is preferably made of copper, or some other conductive material. The contactor 48 is engageable with a plurality of contacts 51, 52 and 53 mounted on a supporting board or plate 54. The arrangement of the contacts 51, 52 and 53 will be described in detail present y. The board 54 closes one side of the casing 22 and thus forms one wall thereof. The board 54 is preferably made of an insulating material, such as a suitable resinous plastic, but may be made of other suitable materials. In this case, the contact board 54 is secured to the casing 22 by means of a plurality of tabs 56, formed on the upper edges of the side and end walls 27-30. The illustrated tabs 56 project upwardly through notches or slots 58 in the edge portions of of the contact board 54. To retain the board 54, the upper ends of the tabs 56 are suitably spread or clinched.

The contactor 48 is preferably biased outwardly toward the contacts 51-53 by resilient means in the form of a coiled compression spring 60, acting between the contactor and the carriage 32. A well or socket 62 is preferably formed in the carriage 32 to receive and locate the spring 60.

The illustrated contactor 48 is slidably mounted on the carriage 32 for outward movement against the contacts 51-53. As shown, the contactor 48 is slidably guided and confine-d within a recess or slot 64, formed in the upper portion of the carriage 32. The recess 64 is formed between the longitudinal wall portions 39 and 40 of the carriage 22.

The illustrated contactor 48 is in the form of a generally rectangular plate-like member. The contactor 48 has opposite longitudinal edges 66 and 67 which are slidably engageable with the side wall portions 39 and 40 of the carriage 32.

To form precision coupling means between the carriage 32 and the contactor 48, at least one notch or slot is formed in the contactor 48, for slidabl eceiving a corresponding lug or guide bar on the carriage. In the illustrated construction, the contactor 48 is provided with two such slots or notches 68 and 69, formed in the opposite edge portions 66 and '67 of the contactor 48. Corresponding lugs or guide bars 70 and 71 are formed on the carriage 48. It will be seen that the lugs 70 and 71 are slidably received in the notches 68 and 69. The illustrated lugs 70 and 71 project toward each other and into the recess 64 from the side wall portions 39 and 40 of the carriage 48. It will be seen that the lugs or guide bars 70 and 71 extend in the direction in which the contactor 48 is slidably movable relative to the carriage 32. Thus, the lugs 70 and 71 extend at right angles to the direction of movement of the carriage 32.

A close sliding fit is preferably provided between the notches 68 and 69 and the lugs 70 and 71, so that there will be a minimum of lost motion or play between the contactor 48 and the carriage 32. Thus, the contactor 48 follows the movement of the carriage 32 with a high degree of precision.

The contacts 51-53 may assume various forms but are illustrate-d as the rounded heads of rivets 81, 82 and 83, extending through openings 91, 92 and 93 in the insulating contact board 54. Terminals 94 are mounted on the rivets 81-83, on the outer side of the contact board 54. There are two of the terminals 94, but they are preferably identical in construction, as will be described in detail presently.

The contact 51 is illustrated as being in the form of an isolated or single contact, disposed at a first point along the path of movement of the contactor 48. The contacts 52 and 53 are paired on opposite sides of a second point spaced along such path of movement from the first point.

Each of the illustrated terminals 94 is in the form of an L-shaped member having two flanges 96 and 98. The flange 96 is formed with an opening 101, adapted to receive the contact rivet 81, and a pair of openings 102 and 103, adapted to receive the rivets 82 and 83. The openings 102 and 103 are spaced on opposite sides of the opening 101. The flange 98 of the terminal 94 provides an outwardly projecting prong, adapted to receive a connector or the like.

In the case of the terminal 94 mounted on the rivet 81, the central opening 101 is used. In the case of the terminal 94 mounted on the rivets 82 and 83, the outwardly spaced openings 102 and 103 are used. Thus, the same terminal construction is applicable to both situations. This arrangement facilitates the manufacture of the switch and obviates any error in the assembly of the terminals on the rivets.

It will be seen that the illustrated terminal 94 is formed with a prong or flange 106 which is bent downwardly from the flange 96, adjacent the opening 101. As shown to best advantage in FIGS. 4 and 6, the prong .106 is adapted to be received in a slot 108 extending laterally from the opening 91 in the insulating contact board 54. The prong 106 acts as a key to prevent the terminal 94 from rotating about the rivet 81. When the terminal 94 is used on the rivets 82 and 83, the prong 106 merely engages the upper side of the insulating board 54, and is bent upwardly by the clinching of the rivets 82 and 83.

To guide the contactor 48, the insulating contact board 54 is preferably formed with insulating bosses 110 and 112 which project from the inner side of the board. The boss 110 is disposed near the contacts 52 and 53, and on the line of symmetry extending therebetween from the single contact 51. The second boss 112 is disposed between the first boss 110 and the single contact 51. The bosses 1 10 and 112 are preferably in the form of semiperforations, extruded or punched from the insulating board 54.

The plunger 34 of the carriage 32 is preferably formed with an opening 114 for receiving a temporary stop pin 116. It will be seen that the stop pin 116 is engageable with the end wall 30 of the casing, when the plunger 34 is depressed. A notch 118 is formed in the insulating board 54 to receive the pin 116, so that the pin can be moved into full engagement with the end wall 30.

The temporary stop pin 116 is used only in connection with the installation of the switch. The installer positions the switch with the plunger 34 against the brake pedal, and with the plunger 34 depressed so that the pin 116 engages the end wall 30. The switch is then securely mounted in this position, and the pin 116 is removed. The use of the temporary stop pin 116 insures that the switch will be installed with the switch in its off position, when the brake pedal is in its initial or unactuated position.

As shown to best advantage in FIGS. 6 and 7, the illustrated contactor 48 has a first contacting portion 118, an olfset portion 120, and a second contacting position 122. The first contacting portion 118, an offset portion 120, and a second contacting position 122. The first contacting portion 118 is fiat and is adapted to engage the single contact 51. The second contacting portion 122 has rounded end portions 124 and 126, and is adapted to engage the contacts 52 and 53. The offset portion 120 is offset away from the contacts 51-53, and away from the semi-perforated bosses 110 and 112. In this case, the spring 60 engages the offset portion 120.

It will be seen from FIG. 6 that the side wall portions 39 and 40 of the carriage 32 extend into closely spaced relation to the insulating terminal board 54. The same is true of the lugs or guide bars 70 and 71 on the side wall portions 39 and 40. This construction insures that the contactor 48 will be precisely confined and located on the carriage 32 in all positions thereof. The spring 60' biases the contactor 48 against the contacts 51-53, while also biasing the carriage 32 against the lower wall 26 of the casing 22.

It may be helpful to summarize the operation of the switch 20. The return spring 42 tends to bias the carriage 32 against the end wall 30, as shown in full lines in FIG. 6. In this position, the second contacting portion 122 of the contactor engages both of the contacts 52 and 53. The first contacting portion 118 of the contactor engages the single contact 51. Thus, the contactor 48 establishes a closed circuit between the contact 51 and the contacts 52 and 53. Assuming that the switch is used to control the stop lights of an automobile, the stop lights will be energized in this position of the switch.

When the plunger 34 of the switch is depressed to or beyond the position shown in broken lines in FIG. 6, the second contacting portion 122 of the contactor 48 is moved out of engagement with both of the contacts 52 and 53. Thus, an open circuit is produced between the single contact 51 and the dual contacts 52 and 53. Accordingly, the stop lights will be de-energized. When the brake pedal is not actuated, this is the position to which the switch is operated by the brake pedal.

The provision of the dual contacts 52 and 53 is in accordance with the invention disclosed and claimed in the copending application of John E. Soreng and Jesse M. Cobb, Ser. No. 641,920, filed May 29, 1967. The breaking of the circuit between the contactor 48 and the contacts 52 and 53 results in a substantial amount of arcing which causes wear and erosion upon the contactor and the contacts. The provision of the dual contacts 52 and 53 distributes the erosion due to arcing, and greatly prolongs the life of the switch. The breaking of the circuit with the contactor 58 is nearly simultaneous at the contacts 52 and 53, but not absolutely so. Normally, the contactor 48 breaks contact with the contacts 52 and 53 at slightly different instants. It is the second break which actually interrupts the circuit. Thus, the arcing occurs at the contact which is involved in the second break. Such arcing causes a slight erosion, so that the second break shifts to the other contact after a few cycles of operation. Thus, the arcing alternates in a random manner between the two contacts 52 and 53, so that the erosion is distributed. Moreover, the heating effect of the arcing is dissipated to much better advantage.

The contacting portion 122 of the contactor 48 moves from the contacts 52 and 53 and on to the insulating boss 110 which supports the contactor and minimizes rocking movement thereof. The insulating boss 110 makes it easy for the contacting portion 122 to return into engagement with the contacts 52 and 53. The provision of the insulating boss 110 also insures that the arcing between the contacting portion 122 and the contacts 52 and 53 will be in the air, spaced from the insulating board 44, and not along the surface of the insulating board. Thus, the arcs are kept away from the board 54, so that the heat generated by the arcs does not cause burning or other damage to the insulating board.

If the plunger 34 is depressed to an additional extent, the contacting portion 122 rides from the boss to the insulating boss 112. It will be understood that the boss 112 continues to hold the contactor away from the insultaing board 54. Throughout the movement of the carriage 32, the first contacting portion 118 of the contactor 48 engages the single contact 51.

FIGS. 10 and 11 illustrate a modified swtich 220 which is similar to the switch 20 of FIGS. 19, except that the second semi-perforated boss 112 is knocked out of the insulating board 54 and is replaced with an additional contact 222, which is similar in every respect to the single contact 51. Thus, in addition to providing an insulating boss, the semi-perforation 112 provides a knock-out which may readily be removed to provide an opening 224 for the additional contact 222, when a modified switch construction is desired. Another terminal 94 may be mounted on the contact 222, in the same manner as in the case of the single contact 51.

In the modified switch 220, the second contacting portion 122 of the contactor 48 is movable into engagement with the additional contact 222, after moving out of engagement with the contacts 52 and 53. As illustrated in FIG. 10, the additional contact 222 may be connected to a crusing control device 230, or any other desired device. As before, the contacts 52 and 53 are connected to the stop lights 232. The contact 51 is connected to the ungrounded battery terminal 234. The cruising control 230 is a component of the transmission which is to be deactuated as soon as the brake pedal is operated. Thus, the operation of the brake pedal deenergizes the crusing control device 230 and energizes the stop light 232. The cruising control 230 may comprise an overdrive device, a free wheeling device, or the like.

'In the illustrated switches, the contactor 48 is precisely coupled to the carriage 32 by close engagement between the lugs 70 and 71 on the carriage 32 and the notches 68 and 69, formed in the contactor. This construction greatly reduces the lost motion or free play between the carriage and the contactor, so that the contactor follows the carriage with a high order of precision. Thus, the switch is highly dependable and accurate in its operation. This is an important advantage in position-sensing switches, such as brake light switches and the like.

Various other modifications, alternative constructions, and equivalents may be employed without departing from the true spirit and scope of the invention, as exemplified in the foregoing description and defined in the following claims.

I claim:

1. An electrical switch,

comprising a casing,

an insulating carriage movable in said casing,

said casing having a wall with a plurality of contacts mounted thereon,

and a contactor movable with said carriage and engageable with said contacts,

said contactor being in the form of a plate-like member with opposite edges formed with a pair of locating notches,

said carriage having a pair of locating lugs received in said notches and connecting said contactor to said carriage for movement therewith,

said lugs projecting toward each other and generally perpendicular to the path of movement of said carriage.

2. An electrical switch,

comprising a casing,

an insulating carriage movable in said casing,

said casing having a wall with a plurality of contacts mounted thereon,

and a contactor movable with said carriage and engageable with said contacts,

said contactor being in the form of a plate-like member with opposite edges formed with a pair of locating notches,

said carriage having a pair of locating lugs received in said notches and connecting said contactor to said carriage for movement therewith,

said carriage comprising a recess with opposite walls confining and guiding said opposite edges of said contactor.

3. An electrical switch,

comprising the combination of a casing,

an insulating carriage movable in said casing,

said casing having a wall with a plurality of contacts thereon,

a contactor movable with said carriage and engageable with said contacts,

said contactor having at least one locating slot therein,

said carriage having at least one lug received in said slot and locating said contactor on said carriage for movement therewith,

and resilient means on said carriage and biasing said contactor outwardly toward said contacts,

said lug being slidably received in said slot to provide for the outward movement of said contactor.

4. An electrical switch,

comprising the combination of a casing,

an insulating carriage movable in said casing,

said casing having a wall with a plurality of contacts thereon,

a contactor movable with said carriage and engageable with said contacts,

said contactor having at least one locating slot therein,

said carriage having at least one lug received in said slot and locating said contactor on said carriage for movement therewith,

resilient means on said carriage and biasing said contactor outwardly toward said contacts,

and means on said carriage guiding said contactor for outward sliding movement,

said lug being slidably received in said slot to provide for such sliding movement.

5. An electrical switch,

comprising the combination of a generally rectangular casing,

an insulating carriage movable along a linear path in said casing,

said casing having a wall with a plurality of contacts thereon,

portion of said contactor, said lug projecting laterally into said notch. 7. A switch according to claim 5, in which said contactor is formed with a pair of such slots in the form of notches in opposite edge portions of said contactor, and in which said carriage is formed with a plurality of such lugs projecting laterally into said notches. 8. A switch according to claim 7, in which said lugs project toward each other and generally perpendicular to the path of movement of said carriage. 9. A switch according to claim 7, in which said carriage comprises a recess having opposite lateral walls confining the opposite edge portions of said contactor, said lugs projecting toward each other from said opposite lateral walls.

References Cited UNITED STATES PATENTS 2,994,748 8/1961 Long 200-16 XR 3,223,794 12/1965 Hoy et al. 200-16 3,299,227 1/1967 Schaad et a1. 3,303,296 2/1967 Scott. 3,316,364 4/1967 Schink 200-16 3,328,540 6/1967 Zoda et al. ZOO-16 3,329,778 7/1967 Bedocs 20016 ROBERT K. SCHAEFER, Primary Examiner J. R. SCOTT, Assistant Examiner US. Cl. X.R.

P040130 UNITED STATES PATENT OFFICE (569 CERTIFICATE OF CORRECTION Patent No. 3,500,002 Dated March 10, 1970 Inventor(s) M. F Bedocs It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 49, "At least one, and preferably a" should read --Such last motion impairs--.

Column 2, line 42, "with" should read --which--.

Column 5, lines 4 and 5, please cancel "The first contacting portion 118, an offset portion 120, and a second contacting portion 122."

Column 6, line 27, "crusing" should read -cruising-..

Column 6, line 33, "crusing" should read --cruising--.

SIGNED NND SEALED Aueum';

Atteet:

Edward M. MI:- flll I. Attesting Officer llim or m 

